TCP File Transfer behind NAT

[Saurabh]

Dear All,

Can anyone tell me, how to write such a program that can transfer
files (either binary or text) behind NAT devices( such as for
computers behind firewalls and routers and other NAT devices) using
TCP socket programming.

I have a mechanism through which the public IP of the router and Port
number will be forwarded to me. But after that I am not sure that
simple TCP/IP socket programming will suffice or I need to do
something more for that.

If you have any article link or article or any example that shows how
the File Transfer can be done for such a case then please help me
regarding this.

Any sought of help or idea will be appreciated from you all.

from-
Saurabh Srivastava

[Michael DOUBEZ]

Saurabh a écrit :

Dear All,

Can anyone tell me, how to write such a program that can transfer
files (either binary or text) behind NAT devices( such as for
computers behind firewalls and routers and other NAT devices) using
TCP socket programming.

I have a mechanism through which the public IP of the router and Port
number will be forwarded to me. But after that I am not sure that
simple TCP/IP socket programming will suffice or I need to do
something more for that.

If you have any article link or article or any example that shows how
the File Transfer can be done for such a case then please help me
regarding this.

Any sought of help or idea will be appreciated from you all.

Asking in a network programming or os specific group would help you more.

FYI NAPT services are transparent from the public network point of view
so unless you are using some complex tunneling system you simply address
a service (protocol/port number) of the front end and it will forward it
to the internal server transparently. When the protocol includes some
address related information (like FTP), there are some applet modules on
the frontend router that will make the translation at the application
level. That might be a problem if you are using a secured communication.

Therefore, in general and in your case, simple TCP/IP socket programming
is sufficient.

Nothing to do with C++.

Michael